C :

#include <stdio.h>
int main(){
	int n,tmp,i,m,a[500];
//	freopen("1.txt","r",stdin);
	while (scanf("%d %d",&n,&m)!=EOF)
	{
		for (i=0;i<n;i++)
		{
			scanf("%d",&a[i]);
		}
		while (m--)
		{
			scanf("%d",&tmp);
			for (i=n-1;i>=0;i--)
			{
				if (tmp==a[i])
				{
					printf("%d ",i);
					break;
				}
			}
			if (i==-1)
			{
				printf("-1 ");
			}
		}
		printf("\n");
	}
//	fclose(stdin);
	return 0;
}

C++ :

#include <cstdio>
#include <cstdlib>
#include <stack>
#include <algorithm>
using namespace std;
const int MAXN = 500;
int val[MAXN + 1];
int main() {
	int n, k, position, query;
	scanf("%d%d", &n, &k);
	for (int i = 0;i < n;i++) {
		scanf("%d", &val[i + 1]);
	}
	for (int i = 0;i < k;i++) {
		scanf("%d", &query);
		val[0] = query;
		position = n;
		while (val[position] != query) position--;
		printf("%d ", position - 1);
	}
	puts("");
	return 0;
}